The second part of your question - vpclog is a Vodaphone log, which as you say will grow larger all the time. To get rid of it involves changing the registry, and as you are posting on the Beginners forum this might be too scary for you. If you mess up the registry then your troubles will just be starting!
These instructions should sort out the problem, but if you don't feel confident perhaps you know somebody who could help you out. Assuming you are using XP firstly back up the registry, and then
Click on Start and then click on Run...(usually bottom right)
enter : 'regedit' and click OK
the registry editor window will open, it looks like a file explorer window (but do not go mucking about in here unless you really know what you are doing)
expand the folder HKEY_CURRENT_USER
expand the folder Software
expand the folder Vodafone
click on folder VCMLite
in the right hand window double click on 'use_logging' (about 2/3 of the way down the list)
the Edit DWord Value window will open
Change the Value Data: setting from '1' to '0' and click OK
close the Registry Editor by clicking the top right red cross
go back into My documents folder and delete the Vpclog.txt file
You are done, logging turned off and file deleted.